Add Yahoo as a preferred source to see more of our stories on Google. The Andromeda galaxy helped Edwin Hubble settle a great debate in astronomy. Stocktrek Images via Getty Images A hundred years ago ...

If we could go back 101 years, we would encounter a time when scientists still thought the Milky Way was the entirety of our universe. But, if we went back 100 years instead, we would find most ...

This article was originally featured on The Conversation. A hundred years ago, astronomer Edwin Hubble dramatically expanded the size of the known universe. At a meeting of the American Astronomical ...